Exhaust manifold for internalcombustion engines



EXHAUST MANIFOLD FOR INTERNAL-COMBUSTION ENGINES Filed May 4, 1945INVENTOR.

Pierre [rmsi fiera'er sine and j Patented Nov. 13,1945

EXHAUST MANIFOLD FOR INTERNAL- 4 COMBUSTION ENGINES Pierre ErnestMereler, New York, N. x. Application May 4, 1943, Serial No. 485,593

'1 Claims. ('01. 60-29) This invention relates to improvements inexshocks and to compensate for unequal thermal haust manifolds forinternal combustion engines, and particularly to exhaust manifolds ofmulticyllnder engines for aircraft and other types of self-propelledvehicles wherein pronounced vibrations and stresses are apt to be set upin the connections of the manifold to the cylinders because of shocksimparted to the vehicle, unequal thermal expansion from the heat of theexhaust gases, and other incidents of the operation of the en'- l ne.

Exhaust manifold systems as heretofore em ployed in aircraft engineshave taken different forms depending somewhat upon the type of enthespace requirements. In some cases the manifold has been mounted directlyadjacent the exhaust ports, and while this has proved to be an advantagefrom the standpoint of space economy, it has not been a good solutionfrom the standpoint of facilitating cooling of the en ine by the passingair. The disadvantages of such arrangements are increased when multi-rowradial engines are involved. To improve the air cooling, therefore, manyexhaust manifolds are disposed in spaced relation to the engine andconnected to the individual exhaust ports by short individual pipeconnections. However, this arrangement has created a problem ofeffecting gas tight connections with the engine cylinders that maybequickly and easily broken when it is desired to remove or replace themanifold. It is also found that stresses are set up between the elementsof the connections due to vibrations and shocks and to unequal thermalexpansion of the manifold branch pipes with respect to the manifoldproper and the engine port connections with which they are joined. Whensuch manifold structures are rigidly Joined to the several enginecylinders as has been the practice in the past. failures eventuallyoccur where the stress has become too great in one of the connectionsbecause of the combination of the above mentioned factors.

In my copending application Serial No. 424,219, now Patent No.2,318,006, I have disclosed and claimed an improved coupling designed toestablish a flexible connection between two conduits or between anexhaust manifold connecting pipe and an engine exhaust port. In myaforesaid patent I have also disclosed one form of the improved manifoldstructure being claimed herein, and to I provide an improved coupling:lacent pipes, such, for example,

connections wherein to the cylinders that may be expansion of theconnecting pipes. A

It is a further object of the invention to provide an exhaust manifoldwith individual connections quickly and easily assembled without the useof bolts or rivets and which may be easily dismantled.

-It is' a still further as used in an exhaust manifold system or betweenan exhaust manifold connection and an engine cylinder, and whichcoupling is designed to maintain a sealing relationship at the point 'ofJunction of the two pipes under varying conditions of temperature and ofshock or vibration.

It is still another-object of my invention to provide an improvedcoupling for exhaust manifold thermal expansion caused by the hot gasesis localized and controlled to promote the sealing effect of theelements makin up the coupling.

, aircraft engine:

- only three cylinders are such extent this application is acontinuation-inpart of my copending application aforesaid.

It is an object of the invention to provide. an exhaust manifold withconnections to the several cylinders of the engine manifold remainsfirmly secured in position to perform its function while at the sametime permitting of limited freedom of movement at the connectionssuflicient to absorb vibrations and 60 scribed and claimed in my thatwill insure that the V Fig. 2 is a partial rear elevation of a singlerow radial engine showing the application of my improvedmanifoldthereto;

Fig. 3 is a schematic plan view or my manifold applied to a double rowradial engine; and

Fig. 4 is a longitudinal section illustrating certain features-of the.

Referring to Fig. 1, the manifold i0 is shown as having three branchesII, I! and it connected by means of the flanges l4, l5 and i6 with threeadjacent cylinders of an in-line engine. Although shown, it will beunderstood that the arrangement will be similar when a larger number ofcylinders are to be accommodated by a single manifold. As shown, thecentral branch pipe II of the manifold is rigidly connected to thecylinder head or other fixed part of the engine block according todesign, by means of a central flange l5.

The two end branches to the head by means of flexible couplings H whichpermit of considerable relative movement of the ends of the branch pipesIt and it both lengthwise of the axis of the engine port and theconnection thereof with the manifold and which are also movablepi'votally about a point defined roughly by the intersection of thelongitudinal axis and a line passing through the plane of the coupling.

The couplings are shown as of the type de- Patent No. 2,318,006,

object of the invention to between two adimproved coupling used in themodification of Fig. 3.

II and ii are connected see Fig. thereof, but it will be understood thatthey may be of any other suitable design combining the advantages of alimited flexibility and gas tightness in all conditions of operation. Itwill also be observed that the branches of the manifold are smoothlycurved rearwardly where they merge in the body of the manifold which isproressively enlarged so as to acccmmodate the successive increments ofexhaust sues without set-- ting up undue turbulence in the flow thereof.

By rigidly connecting the manifold at only one cylinder while providingflange connections at the adjacent cylinders, the positioning .of themanifold in a determined positim with respect to the engine is assured,while at the same time the flexible couplings permit of adjustments ofthe relative positions of the branches I I and I 3 and the main body ofthe manifold with respect to the fixed central branch I2 under theinfluence of differences in thedegree 01' expansion of the manifoldconnections on account of the different temperatures of the parts of themanifold and the parts to which'they are connected by the flanges andthe diflferent temperatures of different manifold connections and themain body of the manifold under operating conditions,

In Fig. 2 my improved exhaust manifold mounting is shown as applied to asingle row radial engine 23. .The manifold Ila isshown as graduallyexpanded from its point of attachment to the cylinder 2| so as toaccommodate in a simple manner and without creating back pressure thegases from the successive cylinders 22, 23, etc. The branch No to therespective cylinder heads 2Ia, 22a and 23a are made through the mediumof attachment flanges carrying attachment plates 2Ib, 22b, and 23bmounted on the respective cylinder heads. The couplings by which thebranches of the manifold are connected to the respective exhaust portsare not shown in this view, being back of the body of the exhaustmanifold I Ila. It will be understood, however, that they may take theform of the connections illustrated in Fig. 1, i. e., one connectionbeing a rigid one and the others being oi the flexible If desired, theflexible connections may take the form of the coupling shown in Fig. 1of my Patent No. 2,318,006 or another suitable design combining theadvantages of the various flexible couplings illustrated in that patentor the form of the coupling shown in Fig. 4 herewith and moreparticularly described hereinafter.

Instead of providing oneor more rigid connections between the manifoldand the engine cylinders as hereinbefore described in referring to Figs.1 and 2, it will be understood that it is within the scope of myinvention to make all of the connections of'the flexible type. When thisis done, it will usually be necessary to provide some additional supportfor the manifold to insure that its position will be maintained underoperating conditions, but such support need not involve rigidconnections. In other words, the advantages of slight adjustabillty ofthe branch connections and of the manifold to one another under thevarying heat expansion conditions may be maintained without setting upundue stresses in any of the elements of the manifold or between themanifold and other parts of the engine to which it is connected and withwhich it must cooperate. By way of example, the manifold may besupported the encircling band 48 type shown in Fig. 1.

attached at III to the supview showing the connections Ila, Ilb and port5i which may be secured as at 32 to the housing of the engine 20 (seeFig. 2).

Fig. 3 is a somewhat exploded or schematic application of m improvedmanifold to a double row radial engine wherein the manifold IIIc isshown as joined to three adjacent cylinders 3|, 32 and 33. Cylinders 3iand 33 are located in the row nearest the exhaust manifold I00 and 32 islocated in the row farthest from the exhaust manifold. The connectionsbetween the manifold and the exhaust ports oi the nearest row ofcylinders 3I. 33. etc., consistof the branch pipes Nd and He joinedthrough the couplings II to the respective engine port flanges ,3Ia and33a. The connections between the manifold and the exhaust ports of thefarthest row of cylinders, which includes cylinder 32, are arrangedthrough the intermediary of the Junction pipe 34 which is connected atone end by a coupling Ila to the adjacent engine port flange and at theother end is connectedto the branch pipe III by means of the flexiblecoupling I3. Coupling Ila may be of a conventional rigid form as shownor may take other forms, as for example that of the coupling shown inFig. l or the coupling shown in Fla. 5 of my aforementioned patent.

Coupling I8 represents an improved construction which permits aconsiderable degree of lateral movement at the joint while at the same-time insuring a tight sealing relationship between the parts at hightemperatures. As shown in Fig. 4, the coupling is used to connect twopipes 35 and 36. the ends 35a an 36a of which are shown as spaced ashort distance from one another to permit of pivoting action between thetwo pipes and also for lengthwise expansion. The coupling I8 consists ofthree main parts, namely a cylindrical collar 31 attached adjacent oneend to the pipe 35 by welding, riveting or other suitable means. Themain portion 31a is free and is slightly spaced concentrically from theouter surface of the pipe 35, forming therebetween an annular slot inwhich is received the end of a sealing collar 38 having at one end acylindrical portion 38a adapted to snugly flt about the end of the pipe35. This cylindrical portion merges into a slightly outwardly flaredportion 38b which continues to expand until it is turned backwardly at39 to form a locking Fixed to the pipe 36 at 4| there is a bell shapedmember 42. This member is joined adjacent its outer end to an inwardlydirected annular strip 44, which is slightly spaced from the member 42on its side nearest the pipe 36, thereby forming a sealing groove 45. aWhen assembled to form a ring 40.

joint or coupling, the turned back portion 33 of member 42 serves to actas acooling fln rapidly by a bracket made up of 1 giving up heat topassing air and establishing a marked temperature gradient between thetemperatllre of the gases passing through the pipe and the temperatureat the rim 43.

Besides functioning to facilitate transfer of heat from the hot exhaustgases to the passing air,

which may be circulated by means of a fan or other means, either solelyfor cooling purposes or to transfer heat from the exhaust gases to theincoming air used to maintain combustion of the fuel introduced into theengine cylinders, the

structural arrangement illustrated serves the further important purposeof causing the sealing collar 38 to be sealed more during operation valswhen the engine is idle. visualized when it is borne in tightly at itstwo ends collars are heated by the exhaust gases they will tend toexpand more rapidly in the areas closer to the pipes 35 and 36 than inthe outer areas where the cooling air has a the extended equalexpansion, free end of the strip ll to be wise, as viewed in Fig. 4, andthe lockin ring 40. and the adjacent tend to expand less than change topass over fin surfaces. Because of the unthere will be a tendency forthe pivoted counterclockpress closer against Likewise the cooling fin llof the collar 31 will the portions thereof portions closer to theconnection with the end of the pipe 85. This will tend to cause the freeend of the collar 31 to bear closer against the sealing member 38 at oradjacent the pivotal axis of the couindicated at It in the drawing aslocated at a point in the longitudinal axes of the pipes 85 and 38 andapproximately equi-distant from the adjacent ends of these pipes.

The coupling i8 will tively light gauge the transmission fins and at thesame gradient between of the main portions of the elements these finsare a part.

generally be made of relasheet metal, thus facilitating of heat topassing air by the time emphasizing the heat these fins and thetemperature of which As a consequence a deforming action is establishedwhich promotes the sealing contact between the loose sealing collar andthe adjacent attached collars.

It will be apparent that my improved coupling has the further advantagethat it may be easily assembled without or boltin and when the engi erecourse to welding, that it may be riveting quickly dismantled is to betaken down for repairs or overhauling.

Although I have emphasized the pivoting action be understood that it hasof permitting considerand contraction withundesired stresses in the pips or with the manifold of an internal fiangeconnection associationsthereof in odifled without departing from the which is not to be deemedlimited by the scope Iclaim:

a multi-cylinder internal combustion englue; in combination, a commonexhaust manifold for a plurality of connecting conduits for thecylinders, nected to of said conduits sponding cylinder by a flexible 2.In a multi-cylinder internal glue; in combination. fold for a pluralidtycylinders having individual exhaust ports of said one of saidconduitsbeing rigidly conits corresponding cylinder and another beingconnected to its correof vin in viduai combination,

' mergin tions therewith at said other conduits, whereby vibrations setup in the operation of said engine will not cause excessive stresses inthe connections between said manifold and said engine.

3. In a multi-cylinder internal combustion englue; in combination, acommon exhaust manifold for a plurality of adjacently arranged cylindershaving the exhaust ports of said cylinders, said conduits being curvedoutwardly and rearwardl manifold being rigidly connected to said engineat only one of said conduits; and having adjustable connectionstherewith at said other conduits, whereby vibrations set up in theoperation of said engine will not cause excessive stresses in theconnections between said manifold and said engine. 4. In amulti-cylinder internal combustion engine; in combination. a commonexhaust manifold for a plurality of adjacently arranged cylinders havingindividual connecting conduits for the exhaust ports of said cylinders,and means establishing flexible connections between said connectingconduits and said engine cylinders.

5. In a multi-row radial aircraft engine; in combination, a commonexhaust manifold for a plurality of adjacently arranged cylinders inpart situated in" one row and in part in an adjacentrow of cylinders,said manifold having individual connecting conduits for the exhaustports of said cylinders, and at least part of said individual connectingconduits being connected to their respective corresponding cylinders byflexible couplin means.

6. In a multi-row radial aircraft engine; in a common exhaust manifoldfor a plurality of adjacently arranged cylinders in part situated in onerow and in part in an adjacent row of cylinders, said manifold beingarranged in spaced relation to said cylinders and havin individualconnecting pipes for the exhaust ports thereof, and flexible couplingmeans joining said connecting pipes to said exhaust ports, said couplingmeans being provided with outwardly projecting heat radiating surfacesadapted to facilitate transmission of heat from the gases passingtherethrough to air circulated about said connecting pipes, and therebypromoting the cooling of said, engine and reducing the heat gradientbetween the wall surfaces of said connecting pi es and the body of saidmanifold.

'I. In a multi-row radial aircraft engine; in combination, a commonexhaust manifold for a plurality'of adjacently arranged cylinders inpart situated in one row and in part in an adjacent row of cylinders,said manifold being arranged in spaced relation to said cylinders andhaving branch pipes integrally joined thereto at one end pipe which inturn is portofthemoredistantrowofcylindere.

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